HD32.1
- 10 -
V2.1
The discomfort from air current is defined as an undesired local cooling of the body due to air
motion. The
DR
indicates the percentage of unsatisfied people due to air current.
The
DR
index is
calculated when the temperature goes from 20 °C to 26 °C and the average wind speed is < 0.5
m/s.
The
DR
index is calculated using the DeltaLog10 software.
2.1.3 WCI Index
WCI
(Wind Chill Index) allows a synthetic evaluation of the effects of cold environments on man.
It shows the cooling index due to the wind. It allows evaluating the discomfort perceived during
exposure to low temperatures and wind. The index does not consider the clothing and the work
intensity.
The WCI index is calculated by the instrument in presence of air under 10°C.
The WCI index calculation formula is:
WCI = 13.12 + 0.6215 t
a
– 11.37 v
a
0.16
+ 0.4275 t
a
v
a
0.16
where:
t
a
: air temperature (in °C);
v
a
: Wind speed (in km/h) calculated at 10 m from the ground.
As the instrument measures the wind speed at 1.5 m from the ground, the formula is corrected as
follows:
WCI = 13.12 + 0.6215 t
a
– 11.37(1.5 v
1.5
)
0.16
+ 0.4275 t
a
(1.5 v
1.5
)
0.16
where
v
1.5
is the wind speed measured by the instrument at 1.5 m from the ground.
The following tables report some WCI values and the relevant frostbite risks (source: NOAA –
National Weather Service).
Air temperature °C
10 5 0 -5 -10 -15 -20 -25 -30 -35 -40 -45 -50
10 8.6 2.7 -3.3 -9.3
-15.3
-21.1
-27.2
-33.2 -39.2 -45.1 -51.1 -57.1 -63.0
15 7.9 1.7 -4.4
-10.6
-16.7
-22.9
-29.1 -35.2 -41.4 -47.6 -51.1 -59.9 -66.1
20 7.4 1.1 -5.2
-11.6
-17.9
-24.2
-30.5 -36.8 -43.1 -49.4 -55.7 -62.0 -68.3
25 6.9 0.5 -5.9
-12.3
-18.8
-25.2
-31.6 -38.0 -44.5 -50.9 -57.3 -63.7 -70.2
30 6.6 0.1 -6.5
-13.0
-19.5
-26.0
-32.6 -39.1 -45.6 -52.1 -58.7 -65.2 -71.7
35 6.3 -0.4 -7.0
-13.6
-20.2
-26.8
-33.4 -40.0 -46.6 -53.2 -59.8 -66.4 -73.1
40 6.0 -0.7 -7.4
-14.1
-20.8
-27.4
-34.1 -40.8 -47.5 -54.2 -60.3 -67.6 -74.2
45 5.7 -1.0 -7.8
-14.5
-21.3
-28.0
-34.8 -41.5 -48.3 -55.1 -61.8 -68.6 -75.3
50 5.5 -1.3 -8.1
-15.0
-21.8
-28.6
-35.4 -42.2 -49.0 -55.8 -62.7 -69.5 -76.3
55 5.3 -1.6 -8.5
-15.3
-22.2
-29.1 -36.0 -42.8 -49.7 -56.6 -63.4 -70.3 -77.2
W
in
d
sp
ee
d
v
a
K
m
/h
60 5.1 -1.8 -8.8
-15.7
-22.6
-29.5 -36.5 -43.4 -50.3 -57.2 -64.2 -71.1 -78.0
The values that can cause frostbite within
≤
30 minutes are reported in bold.
Summary of Contents for HD32.1
Page 6: ...HD32 1 6 V2 1 Thermal Microclimate HD32 1...
Page 78: ...HD32 1 78 V2 1 MIN 350 MAX 1020 120 AP471 S4...
Page 106: ...HD32 1 106 V2 1 Moderate Environment Norm ISO 7730...
Page 107: ...HD32 1 107 V2 1 Moderate Environment Norm ISO 7730...
Page 108: ...HD32 1 108 V2 1 Moderate Environment Norm ISO 7730...
Page 109: ...HD32 1 109 V2 1 Moderate Environment Norm ISO 7730...
Page 110: ...HD32 1 110 V2 1 Moderate Environment Norm ISO 7730...
Page 111: ...HD32 1 111 V2 1 Moderate Environment Norm ISO 7730...
Page 112: ...HD32 1 112 V2 1 12 2 WARM ENVIRONMENT Norm ISO 7243 Norm ISO 7243...
Page 113: ...HD32 1 113 V2 1 Warm Environment Norm ISO 7243...
Page 114: ...HD32 1 114 V2 1 Warm Environment Norm ISO 7243 Norm ISO 7243...
Page 115: ...HD32 1 115 V2 1 Warm Environment Norm ISO 7243...
Page 116: ...HD32 1 116 V2 1 Warm Environment Norm ISO 7243...
Page 117: ...HD32 1 117 V2 1 Warm Environment Norm ISO 7243...
Page 118: ...HD32 1 118 V2 1 12 3 DISCOMFORT ANALYSIS Norm ISO 7730 Norm ISO 7730...
Page 119: ...HD32 1 119 V2 1 Discomfort Analysis Norm ISO 7730...
Page 120: ...HD32 1 120 V2 1 Discomfort Analysis Norm ISO 7730...
Page 121: ...HD32 1 121 V2 1 Discomfort Analysis Norm ISO 7730...
Page 122: ...HD32 1 122 V2 1 Discomfort Analysis Norm ISO 7730...
Page 123: ...HD32 1 123 V2 1 Discomfort Analysis Norm ISO 7730...
Page 124: ...HD32 1 124 V2 1 Discomfort Analysis Norm ISO 7730...
Page 125: ...HD32 1 125 V2 1 12 4 HOT ENVIRONMENT Norm ISO 7933 Norm ISO 7933...
Page 126: ...HD32 1 126 V2 1 Hot Environment Norm ISO 7933...
Page 127: ...HD32 1 127 V2 1 Hot Environment Norm ISO 7933...
Page 128: ...HD32 1 128 V2 1 Hot Environment Norm ISO 7933...
Page 129: ...HD32 1 129 V2 1 Hot Environment Norm ISO 7933...
Page 130: ...HD32 1 130 V2 1 Hot Environment Norm ISO 7933...
Page 131: ...HD32 1 131 V2 1 Hot Environment Norm ISO 7933...
Page 132: ...HD32 1 132 V2 1 12 5 COLD ENVIRONMENT Norm ISO 11079 Norm ISO 11079...
Page 133: ...HD32 1 133 V2 1 Cold Environment Norm ISO 11079...
Page 134: ...HD32 1 134 V2 1 Cold Environment Norm ISO 11079...
Page 135: ...HD32 1 135 V2 1 Cold Environment Norm ISO 11079...
Page 136: ...HD32 1 136 V2 1 Cold Environment Norm ISO 11079...
Page 137: ...HD32 1 137 V2 1 Cold Environment Norm ISO 11079...
Page 138: ...HD32 1 138 V2 1 Cold Environment Norm ISO 11079...
Page 139: ...HD32 1 139 V2 1 Cold Environment Norm ISO 11079...
Page 140: ...HD32 1 140 V2 1 12 6 PHYSICAL QUANTITIES...
Page 153: ...HD32 1 153 V2 1 NOTES...
Page 154: ...HD32 1 154 V2 1 NOTES...
Page 155: ......
